RADIOSONDE PENETRATION OF AN UNDILUTE CUMULONIMBUS ANVIL Academic Article uri icon

abstract

  • An example is presented of the serendipitous radiosonde penetration through the western edge of a rapidly growing undilute cumulonimbus anvil above 200 mb by an operationally released radiosonde balloon. The sounding is supportive of deep convection and contains a stable layer (13C potential temperature increase) from 210 to 185 mb with a quasi-adiabatic mixed layer from there to 135 mb. The 185135-mb layer has a wet-bulb potential temperature of 24C which agrees to within 1C of the subcloud-layer wet-bulb potential temperature. The wind perturbation of approximately 30 m s1 within the mixed layer is larger than, but consistent with, relative outflow velocities estimated from satellite imagery and density current theory. Downstream soundings through decaying anvil debris 12 h later still show evidence of the initial convective thermal perturbation even as the tropopause attempts to reform in the vicinity of 200 mb. Implications for the tropospheric-stratospheric exchange of water vapor and the measurement of water vapor at cold temperatures are discussed. The present operational practice of not reporting moisture data at high levels in the troposphere when the ambient temperature is less than 40C deprives users of potentially useful moisture information.

published proceedings

  • MONTHLY WEATHER REVIEW

author list (cited authors)

  • BOSART, L. F., & NIELSEN, J. W.

citation count

  • 7

complete list of authors

  • BOSART, LF||NIELSEN, JW

publication date

  • June 1993